[Affected versions] 63.0a1 (2018-08-19) [Affected platforms] Windows 10, Windows 7, Ubuntu 16.04, Mac OS X [Steps to reproduce] 1. Open Firefox and in the Hamburger Menu, click on Content Blocking 2. about:preferences#privacy will be opened and Content Blocking section will be focused 3. Set Slow tracking element to "Never block" 4. Set Trackers to "Always block" 5. Access https://store.kaspersky.com/store?Action=buy&Currency=EUR&Locale=en_FI&SiteID=kaspergl&ThemeID=5035600&productID=310017800&quantity=1&spage=&undefined=Home_Home-Products_Kaspersky-Password-Manager [Expected result] Content of page is rendered as expected [Actual result] Besides the simple HTML content, the page is blocked and not being rendered